Sending email error

[Katherine]

Account: 'pop-server.satx.rr.com', Server: 'smtp-server.satx.rr.com',
Protocol: SMTP, Server Response: '501 5.5.2 RCPT TO syntax error', Port: 25,
Secure(SSL): No, Server Error: 501, Error Number: 0x800CCC79

 

[Gary VanderMolen \(MVP\)]

That's not the complete error message. The first part is missing.
From the fragment you supplied it appears that the recipient's
email address may have contained an illegal character.
Can you send emails to yourself, or to other recipients besides
this one?